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1.
Int J Med Mushrooms ; 22(6): 547-558, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32865896

RESUMEN

This study was designed to understand the effect of extraction temperature, i.e., room temperature (GLRT), 50°C (GL50), 100°C (hot water; GL100), and 200°C (GL200) on antioxidant and biological activity of G. lucidum. The % yield obtained was 5.3%, 7.6%, 10.7%, and 13.2% at various extraction temperatures; room temperature, 50°C, 100°C and 200°C, respectively. Similarly, phenolic content (51.6, 57.9, 82.9, and 93.1 mg/g extract) and flavonoid content (18.8, 23.2, 34.3, and 36.3 mg/g extract) were observed to be increased with rise in extraction temperature. However, extraction temperature resulted in loss of antioxidant activities above 100°C as evident by chemical assays such as DPPH, FRAP, ABTS, and TRP conducted on extracts. In contrast, three bioactive compounds, i.e., adenine (3.26, 3.48, 2.16, and 1.45 mg/g extract), uracil (3.99, 3.21, 2.51, and 1.47 mg/g extract), and adenosine (5.92, 5.62, 2.22 and 0.7 mg/g extract), quantified by high performance thin layer chromatography showed decrease in their content with increasing extraction temperature. Extract prepared at room temperature and 50°C prevented loss of cell viability and generation of reactive oxygen species resulted after hydrogen peroxide exposure; however, cytoprotective efficacy was not significant at 100°C and 200°C The order of cytoprotective effects observed by these extract were in the following order: room temperature ≥ 50°C > 100°C > 200°C. Overall, the optimal temperature conditions for the efficient extraction of G. lucidum with water retaining bioactive compounds and biological activity was found to be below 100°C.


Asunto(s)
Antioxidantes/farmacología , Productos Biológicos/farmacología , Citoprotección , Estrés Oxidativo , Reishi/química , Adenina/análisis , Adenosina/análisis , Animales , Muerte Celular , Línea Celular , Flavonoides/análisis , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Peróxido de Hidrógeno/toxicidad , Ratones , Fenoles/análisis , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/metabolismo , Temperatura , Uracilo/análisis
2.
PLoS One ; 10(11): e0141796, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26536126

RESUMEN

Schizosaccharomyces pombe Δura4 cells lyse when grown on YPD medium. A S. pombe non-essential gene deletion library was screened to determine suppressors of the lysis phenotype. Deletion of the pub1 gene, which encoded E3 ubiquitin ligase, strongly suppressed cell lysis in Δura4 cells. The Δpub1 cells displayed high sensitivity to 5-fluorouracil, a toxic analog of uracil, and this sensitivity was suppressed by deletion of fur4, which encoded a uracil transporter. Fur4 localized primarily to the Golgi apparatus and vacuoles in wild-type cells, but localization was predominantly at the plasma membrane in Δpub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of Δura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.


Asunto(s)
Ligasas de Carbono-Nitrógeno/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Ligasas de Carbono-Nitrógeno/genética , Membrana Celular/metabolismo , Cromatografía Líquida de Alta Presión , Regulación hacia Abajo , Fluorouracilo/análisis , Fluorouracilo/metabolismo , Eliminación de Gen , Aparato de Golgi/metabolismo , Espectrometría de Masas , Microscopía Fluorescente , Mutación , Proteínas de Schizosaccharomyces pombe/genética , Ubiquitinación , Uracilo/análisis , Vacuolas/metabolismo
3.
Toxicon ; 103: 48-54, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26091872

RESUMEN

Adsorption of mixtures of cyanotoxins onto sediment as a dominant mechanism in the elimination of cyanotoxins from the aqueous phase has not been extensively investigated. The aim of this study was to investigate adsorption and desorption behavior of six microcystins including microcystin (MC)-LR, RR, YR, LY, LW and LF and cylindrospermopsin (CYN) on natural sediment. Freundlich and Langmuir isotherms could be fitted for MC-LR, RR, YR and CYN. Sorption kinetics showed immediate rapid adsorption for all cyanotoxins: CYN, MCLW and MCLF were adsorbed 72.6%, 56.7% and 55.3% respectively within 2 h. Results of desorption experiments demonstrated that less than 9% of cyanotoxins desorbed from sediment within 96 h. Adsorption of cyanotoxins onto three fractionated sediments particles, clay-silt (<75 µm), find sand (75-315 µm) and coarse sand (315-2000 µm) demonstrated that adsorption capacity of coarse sand fraction for all the tested cyanotoxins was less than 4% of the clay-silt fraction. Results of this study revealed that there is a potential for cyanotoxins to accumulate in the sediments of lakes, as well as in drinking water treatment plants. Monitoring programs must consider cyanotoxins in the particulate phase to avoid largely underestimating toxin concentrations following their release from blooms.


Asunto(s)
Agua Potable/química , Sedimentos Geológicos/análisis , Microcistinas/análisis , Uracilo/análogos & derivados , Purificación del Agua , Alcaloides , Toxinas Bacterianas , Cianobacterias/metabolismo , Toxinas de Cianobacterias , Lagos , Toxinas Marinas , Uracilo/análisis , Contaminantes Químicos del Agua
4.
Zhong Yao Cai ; 38(11): 2269-73, 2015 Nov.
Artículo en Chino | MEDLINE | ID: mdl-27356374

RESUMEN

OBJECTIVE: To establish a method for simultaneous determination of nucleosides and nucleobases in natural, cultured and tissue culture Anoectochilus roxburghii by high performance liquid chromatography-electrospray ionization/ion trap mass spectrometry (HPLC-ESI/MS). METHODS: The separation was performed on a Welch Ultimate XB-C18 column (250 mm x 4.6 mm,5 µm). 20 mmol/L ammonium acetate solution and methanol were adopted as the mobile phase with gradient elution. The flow rate was 1.0 mL/min. The injection volume was 20 µL. The column temperature and UV wavelength were set at 30 degrees C and 260 nm, respectively. RESULTS: Cytosine, uracil, cytidine, uridine, hypoxanthine, adenine, inosine, guanosine,fl-thymidine and adenosine were identified in natural, cultured and tissue culture Anoectochilus roxburghii. The total content of nucleosides and nucleotides in Anoectochilus roxburghii were 1.6639, 1.8568 and 2.2013 mg/g,respectively. CONCLUSION: The contents of nucleosides and nucleobases in herb are affected by its growth pattern. The total content of nucleosides and nucleotides was tissue culture herb > cultured herb > natural herb. This investigation would provide the theoretic basis for quality standards and applications of Anoectochilus roxburghii in clinical research.


Asunto(s)
Nucleósidos/análisis , Nucleótidos/análisis , Orchidaceae/química , Adenina/análisis , Adenosina/análisis , Cromatografía Liquida , Medicamentos Herbarios Chinos/química , Guanosina/análisis , Hipoxantina/análisis , Espectrometría de Masas , Uracilo/análisis , Uridina/análisis
5.
J Chromatogr Sci ; 52(8): 852-61, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23983242

RESUMEN

A liquid chromatography-triple-quadrupole linear ion trap mass spectrometry (LC-QTrap-MS) analysis has been developed for the identification and quantification of 10 nucleosides and nucleobases in extracts of Antrodia camphorata. The method was successfully used to qualitatively identify for six nucleosides namely, cytidine, uridine, inosine, guanosine, thymidine, adenosine and four nucleobases namely, uracil, guanine, xanthine, adenine in A. camphorata. Under optimized chromatographic conditions, good separation for 10 target compounds were obtained on an Agilent HC-C18(2) column (4.6 × 250 mm, 5 µm) eluted by a mobile phase of 5 mM ammonium acetate solution-methanol at a flow rate of 0.5 mL/min. Data acquisition was carried out in multiple reaction monitoring transition mode. Additional identification and confirmation of target compounds were performed using the enhanced product ion modus of the linear ion trap. It was the first report about simultaneous analysis of nucleosides and nucleobases in A. camphorata using this method. These results demonstrated that the QTRAP LC-MS/MS was a useful tool for quality evaluation of some medicinal plant products by using nucleosides and nucleobases as chemical markers. This method might also be utilized for the investigation of edible plant materials and agricultural products containing nucleosides and nucleobases.


Asunto(s)
Adenina/análisis , Antrodia/química , Cromatografía Liquida/métodos , Guanina/análisis , Nucleósidos/análisis , Espectrometría de Masas en Tándem/métodos , Uracilo/análisis , Xantina/análisis , Extractos Vegetales/análisis , Reproducibilidad de los Resultados
6.
Artículo en Inglés | MEDLINE | ID: mdl-21623503

RESUMEN

For the analysis of blue-green algal food supplements for cylindrospermopsin (CYN), a C18 solid-phase extraction column and a polygraphitized carbon solid-phase extraction column in series was an effective procedure for the clean-up of extracts. Determination of CYN was by liquid chromatography with ultraviolet light detection. At extract spiking levels of CYN equivalent to 25-500 µg g(-1), blue-green algal supplement recoveries were in the range 70-90%. CYN was not detected in ten samples of food supplements and one chocolate product, all containing blue-green algae. The limit of detection for the method was 16 µg g(-1), and the limit of quantification was 52 µg g(-1).


Asunto(s)
Toxinas Bacterianas/análisis , Carcinógenos/análisis , Cianobacterias/metabolismo , Suplementos Dietéticos/análisis , Contaminación de Alimentos , Uracilo/análogos & derivados , Alcaloides , Toxinas Bacterianas/aislamiento & purificación , Toxinas Bacterianas/metabolismo , Cacao/química , Dulces/análisis , Carcinógenos/aislamiento & purificación , Carcinógenos/metabolismo , Cromatografía Líquida de Alta Presión , Toxinas de Cianobacterias , Comida Rápida/análisis , Límite de Detección , Extracción en Fase Sólida , Espectrofotometría Ultravioleta , Uracilo/análisis , Uracilo/aislamiento & purificación , Uracilo/metabolismo
7.
Zhongguo Zhong Yao Za Zhi ; 36(11): 1471-3, 2011 Jun.
Artículo en Chino | MEDLINE | ID: mdl-22779180

RESUMEN

OBJECTIVE: To set up the fingerprint of HPCE for medicinal material Eupolyphaga Steleophaga. METHOD: Separation was performed at 25 degrees C on an Agilent uncoated silica capillary column (40 cm x 75 microm) with 20 mmol x L(-1) borax buffer solution (pH 9.44) as CE buffer. The isolating voltage was 13 KV, and the DAD detection was set at 265 nm. RESULT: The characteristic peak of fingerprint of Eupolyphaga Steleophaga was consisted of 6 common peaks. CONCLUSION: The method can be used for the quality control of Eupolyphaga Steleophaga.


Asunto(s)
Electroforesis Capilar/métodos , Insectos/química , Materia Medica/aislamiento & purificación , Animales , Femenino , Medicina Tradicional China/métodos , Control de Calidad , Estándares de Referencia , Uracilo/análisis
8.
Zhongguo Zhong Yao Za Zhi ; 35(17): 2277-80, 2010 Sep.
Artículo en Chino | MEDLINE | ID: mdl-21137337

RESUMEN

OBJECTIVE: To establish a RP-HPLC method for simultaneous determination of thymine, hypoxanthine and uracil contents in medical pipefish. METHOD: Samples were extracted with distilled water by ultrasonic wave and separated on Waters C18 column eluted with a mobile phase of 0.05 mol x L(-1) KFI2PO4-acetonitrile (97:3). The flow rate was 0.6 mL x min(-1). The determination wavelength was 260 nm and the column temperature was set at 40 degrees C. RESULT: The method had good linearity in the range of 0.033-0.660 (r = 0.9996), 0.620-12.400 (r = 0.9999), 0.048-0.960 microg (r = 0.9995), with average recoveries of 98.67% (RSD 1.6%), 99.03% (RSD 0.74%), 98.65% (RSD 1.8%), for thymine, hypoxanthine and uracil respectively. CONCLUSION: The simultaneous determination method of thymine, hypoxanthine and uracil in medical pipefish is established by RP-HPLC for the first time. The contents of the three constituents in different kinds of medical pipefish are significantly different. The method is simple, rapid and sensitive, and can be used for control the quality of medical pipefish.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Hipoxantina/análisis , Medicina Tradicional China , Smegmamorpha , Timina/análisis , Uracilo/análisis , Animales
9.
Nucleic Acids Res ; 38(1): 239-52, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19850724

RESUMEN

MicroRNAs (miRNAs) are 21-22 nucleotide regulatory small RNAs that repress message translation via base-pairing with complementary sequences in the 3' untranslated region (3'UTR) of targeted transcripts. To date, it is still difficult to find a true miRNA target due to lack of a clear understanding of how miRNAs functionally interact with their targeted transcripts for efficient repression. Previous studies have shown that nucleotides 2 to 7 at the 5'-end of a mature miRNA, the 'seed sequence', can nucleate miRNA/target interactions. In the current study, we have validated that the RhoB mRNA is a bona fide miR-223 target. We have analyzed the functional activities of two miR223-binding sites within the RhoB 3'UTR. We find that the two miR-223 target sites in the RhoB 3'UTR contribute differentially to the total repression of RhoB translation. Moreover, we demonstrate that some AU-rich motifs located upstream of the distal miRNA-binding site enhance miRNA function, independent of the miRNA target sequences being tested. We also demonstrate that the AU-rich sequence elements are polar, and do not affect the activities of miRNAs whose sites lie upstream of these elements. These studies provide further support for the role of sequences outside of miRNA target region influencing miRNA function.


Asunto(s)
Regiones no Traducidas 3' , Regulación de la Expresión Génica , MicroARNs/metabolismo , Biosíntesis de Proteínas , Proteína de Unión al GTP rhoB/genética , Adenina/análisis , Secuencia de Bases , Sitios de Unión , Línea Celular , Humanos , Datos de Secuencia Molecular , Proteínas de Unión al ARN/metabolismo , Tristetraprolina/metabolismo , Uracilo/análisis
10.
Biomed Chromatogr ; 23(5): 499-509, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19101922

RESUMEN

Main inborn errors of metabolism diagnosable through uracil (Ura) analysis and the therapeutic monitoring of toxic 5-fluorouracil (5FU) in dihydro pyrimidine dehydrogenase (DPD) deficient patients require a sensitive, reproducible, selective and accurate method. In this work, an artificial receptor in the format of molecularly imprinted polymer (MIP) brush 'grafted to' the surface of sol-gel immobilized on cost-effective homemade solid-phase microextraction (SPME) fibers, individually imprinted with either of Ura and 5FU, was used in combination with a voltammetric sensor duly modified with the same MIP. This combination provided up to 10- and 8.4-fold preconcentrations of Ura and 5FU, respectively, which was more than sufficient for achieving stringent detection limits in the primitive diagnosis of uracil disorders and fluoropyrimidine toxicity in DPD-deficient patients. The proposed method permits the assessment of Ura and 5FU plasma concentrations with detection limits pf 0.0245 and 0.0484 ng mL(-1) (RSD = 1.0-2.5%, S/N = 3), respectively, without any problems of non-specific false-positives and cross-reactivities in complicated matrices of biological samples.


Asunto(s)
Fluorouracilo/análisis , Impresión Molecular/métodos , Microextracción en Fase Sólida/métodos , Uracilo/análisis , Bencenosulfonatos/química , Sitios de Unión , Deficiencia de Dihidropirimidina Deshidrogenasa/diagnóstico , Fluorouracilo/sangre , Fluorouracilo/aislamiento & purificación , Humanos , Microscopía Electrónica de Rastreo , Impresión Molecular/economía , Impresión Molecular/instrumentación , Polímeros/química , Sensibilidad y Especificidad , Microextracción en Fase Sólida/economía , Microextracción en Fase Sólida/instrumentación , Solventes/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Uracilo/sangre , Uracilo/aislamiento & purificación
11.
Zhong Yao Cai ; 31(8): 1142-5, 2008 Aug.
Artículo en Chino | MEDLINE | ID: mdl-19112890

RESUMEN

OBJECTIVE: To study on HPLC fingerprint characteristic analysis of Cordyceps sinensis and its similar products. METHODS: To determinate 13 samples of Cordyceps sinensis and its similar products by HPLC, and analyze the HPLC results with similar appraisal method and graphical methods of multivariate sample in two dimensional plane such as the methods of profile, radar chart and constellation graph. RESULTS: The similar appraisal method might synthesize the similar degree in quantification, while the graphical methods such as profile graph, radar chart and constellation graph could show more details about the classification and the characteristic of varieties directly. CONCLUSIONS: We recommend the combined application of similar appraisal method and the graphical methods due to its advantages on the judgment and characteristic analysis of fingerprint.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Cordyceps/química , Desoxiadenosinas/análisis , Medicamentos Herbarios Chinos/química , Adenina/análisis , Adenina/química , Adenina/aislamiento & purificación , Adenosina/análisis , Adenosina/química , Adenosina/aislamiento & purificación , Cordyceps/clasificación , Desoxiadenosinas/química , Desoxiadenosinas/aislamiento & purificación , Medicamentos Herbarios Chinos/aislamiento & purificación , Polvos , Control de Calidad , Solventes/química , Uracilo/análisis , Uracilo/química , Uracilo/aislamiento & purificación , Uridina/análisis , Uridina/química , Uridina/aislamiento & purificación
13.
J Pharm Biomed Anal ; 44(3): 807-11, 2007 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-17459643

RESUMEN

A high-performance liquid chromatography-diode array detector-mass spectrometry (HPLC-DAD-MS) analytical method was developed for detection of the nucleosides and nucleobases in two species of Lingzhi, the dried sporophore of Ganoderma lucidum and G. sinense. The method, combining advantages of both DAD and MS, was successfully used to qualitatively identify for six nucleosides namely, adenosine, cytidine, guanosine, inosine, thymidine, uridine and five nucleobases namely, adenine, guanine, hypoxanthine, thymine and uracil in Lingzhi samples. Quantitative analyses showed that uridine was the most abundant nucleoside in these Lingzhi samples and the contents of nine target analytes were found to be different in pileus and stipes of the fruiting bodies and among the different species of G. spp. The established method might apply as an alternative approach for the quality assessment of Lingzhi.


Asunto(s)
Adenina/análisis , Cromatografía Líquida de Alta Presión/métodos , Ganoderma/química , Guanina/análisis , Hipoxantina/análisis , Espectrometría de Masas/métodos , Nucleósidos/análisis , Timina/análisis , Uracilo/análisis , Adenina/química , Cuerpos Fructíferos de los Hongos/química , Guanina/química , Hipoxantina/química , Estructura Molecular , Nucleósidos/química , Extractos Vegetales/química , Estándares de Referencia , Reproducibilidad de los Resultados , Especificidad de la Especie , Tecnología Farmacéutica/métodos , Timina/química , Uracilo/química
14.
Electrophoresis ; 28(11): 1681-8, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17464961

RESUMEN

A CEC method is described for the simultaneous determination of 11 nucleosides and nucleobases including cytosine, uracil, uridine, hypoxanthine, 2'-deoxyuridine, inosine, guanosine, thymidine, adenine, adenosine, and cordycepin in Cordyceps using 5-chlorocytosine arabinoside as internal standard (IS). Chemometric optimization based on central composite design was employed to find the optimum conditions. The factors for optimization were defined as three parameters: voltage, pH, and concentration of ACN as organic modifier. The resolution (R(s)) between inosine and guanosine, as well as the entire run time were employed to evaluate the response function. A running buffer composed of 4 mM ammonium acetate and 2 mM triethylamine (TEA) adjusted to pH 5.3 using acetic acid, and containing 3% ACN as modifier, with gradient voltage (0-4 min: 20 kV, 4-12 min: linear gradient from 20 to 30 kV; 12-16 min: 30 kV) were found to be the optimum conditions for the separation. Separation of the 11 investigated compounds and 5-chlorocytosine arabinoside was achieved within 16 min. The contents of the 11 compounds in natural and cultured Cordyceps sinensis, and cultured Cordyceps militaris were also compared. The result showed that CEC is an efficient method for analysis of nucleosides and nucleobases in Cordyceps, which is helpful to control the quality of this valued traditional Chinese medicine.


Asunto(s)
Electrocromatografía Capilar/métodos , Cordyceps/química , Nucleósidos/análisis , Purinas/análisis , Uracilo/análisis , Tampones (Química) , Electrocromatografía Capilar/instrumentación , Concentración de Iones de Hidrógeno , Extractos Vegetales/química , Reproducibilidad de los Resultados , Incertidumbre
15.
DNA Repair (Amst) ; 5(12): 1407-20, 2006 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-16908222

RESUMEN

The steady-state levels of uracil residues in DNA extracted from strains of Escherichia coli were measured and the influence of defects in the genes for uracil-DNA glycosylase (ung), double-strand uracil-DNA glycosylase (dug), and dUTP pyrophosphatase (dut) on uracil accumulation was determined. A sensitive method, called the Ung-ARP assay, was developed that utilized E. coli Ung, T4pdg, and the Aldehyde Reactive Probe reagent to label abasic sites resulting from uracil excision with biotin. The limit of detection was one uracil residue per million DNA nucleotides (U/10(6)nt). Uracil levels in the genomic DNA of E. coli JM105 (ung+ dug+) were at the limit of detection, as were those of an isogenic dug mutant, regardless of growth phase. Inactivation of ung in JM105 resulted in 31+/-2.6 U/10(6)nt during early log growth and 19+/-1.7 U/10(6)nt in saturated phase. An ung dug double mutant (CY11) accumulated 33+/-2.9 U/10(6)nt and 23+/-1.8U/10(6)nt during early log and saturated phase growth, respectively. When cultures of CY11 were supplemented with 20 ng/ml of 5-fluoro-2'-deoxyuridine, uracil levels in early log phase growth DNA rose to 125+/-1.7 U/10(6)nt. Deoxyuridine supplementation reduced the amount of uracil in CY11 DNA, but uridine did not. Levels of uracil in DNA extracted from CJ236 (dut-1 ung-1) were determined to be 3000-8000 U/10(6)nt as measured by the Ung-ARP assay, two-dimensional thin-layer chromatography of metabolically-labeled 32P DNA, and LC/MS of uracil and thymine deoxynucleosides. DNA sequencing revealed that the sole molecular defect in the CJ236 dUTP pyrophosphatase gene was a C-->T transition mutation that resulted in a Thr24Ile amino acid change.


Asunto(s)
ADN Bacteriano/química , Escherichia coli/genética , Uracil-ADN Glicosidasa/genética , Uracil-ADN Glicosidasa/metabolismo , Uracilo/análisis , Proteínas Bacterianas , Biotina/análogos & derivados , Cromatografía Liquida , Cromatografía en Capa Delgada , Medios de Cultivo/química , ADN Bacteriano/metabolismo , Escherichia coli/química , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Genes Bacterianos , Mediciones Luminiscentes/métodos , Espectrometría de Masas , Mutación , Pirimidinas/química , Pirofosfatasas/metabolismo , Estándares de Referencia , Uracilo/metabolismo , Uracil-ADN Glicosidasa/química
16.
Anal Biochem ; 330(1): 58-69, 2004 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-15183762

RESUMEN

Folate deficiency leads to increased dUMP/dTMP ratios and uracil misincorporation into DNA, which may increase cancer risk. We improved a previously described gas chromatography-mass spectrometry (GC-MS) assay for uracil in DNA and validated the assay by analyzing the DNA-uracil content of normal, primary human lymphocytes that were cultured in 0-3000 nM folic acid. In addition, the effects of nucleoside mixtures T or TdCA (T, thymidine; A, adenosine; dC, deoxycytidine) were investigated. Over 4 consecutive days, the inter- and intraassay coefficients of variation (CVs) were 2.3-3.9 and 0.6-2.2%. Mean recovery was 99.4%. Oligonucleotides containing 100 pg of uracil yielded a mean uracil measurement of 110.1 pg (CV=2.7%). Cells grown in different concentrations of folate showed a bimodal response, with maximum DNA-uracil at 12 nM, and minima at 0 and 3000 nM folate. Extremely folate-deficient cells may incorporate less uracil because DNA synthesis is reduced. A wide response to folate deficiency was seen in cells from different donors, suggesting that genetic background plays a critical role in individual susceptibility to DNA damage and cancer risk. Unexpectedly, TdCA supplementation caused increased DNA-uracil (vs 3000 nM folate for 10 days, P > 0.05), probably due to the conversion of deoxycytidine to deoxyuridine by cytidine deaminase, leading to elevated dUMP/dTMP ratios. This improved uracil assay could serve as a useful tool in the study of the mechanism of uracil misincorporation into DNA. The assay requires 3 microg of DNA per folate-deficient sample, but more may be required for baseline DNA-uracil detection in healthy humans.


Asunto(s)
ADN/análisis , Deficiencia de Ácido Fólico , Cromatografía de Gases y Espectrometría de Masas/métodos , Linfocitos/metabolismo , Uracilo/análisis , Células Cultivadas , ADN/metabolismo , Daño del ADN/efectos de los fármacos , Ácido Fólico/metabolismo , Humanos , Nucleósidos/farmacología , Sensibilidad y Especificidad , Uracilo/metabolismo
17.
Free Radic Biol Med ; 29(11): 1115-21, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11121718

RESUMEN

Free radical mechanisms may be involved in the teratogenesis of diabetes. The contribution of oxidative stress in diabetic complications was investigated from the standpoint of oxidative damage to DNA, lipids, and proteins in the livers and embryos of pregnant diabetic rats. Diabetes was induced prior to pregnancy by the administration of streptozotocin (45 mg/kg). Two groups of diabetic rats were studied, one without any supplementation (D) and another treated during pregnancy with vitamin E (150 mg/d by gavage) (D + E). A control group was also included (C). The percentage of malformations in D rats were 44%, higher than the values observed in C (7%) and D + E (12%) animals. D Group rats showed a higher concentration of thiobarbituric acid reactive substances in the mother's liver, however, treatment with vitamin E decreased this by 58%. The levels of protein carbonyls in the liver of C, D, and D + E groups were similar. The "total levels" of the DNA adducts measured, both in liver and embryos C groups were similar to the D groups. Treatment of D groups with vitamin E reduced the levels by 17% in the liver and by 25% in the embryos. In terms of the "total levels" of DNA adducts, the embryos in diabetic pregnancy appear to be under less oxidative stress when compared with the livers of their mothers. Graziewicz et al. (Free Radical Biology & Medicine, 28:75-83, 1999) suggested "that Fapyadenine is a toxic lesion that moderately arrests DNA synthesis depending on the neighboring nucleotide sequence and interactions with the active site of DNA polymerase." Thus the increased levels of Fapyadenine in the diabetic livers and embryos may similarly arrest DNA polymerase, and in the case of this occurring in the embryos, contribute to the congenital malformations. It is now critical to probe the molecular mechanisms of the oxidative stress-associated development of diabetic congenital malformations.


Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Estrés Oxidativo , Embarazo en Diabéticas , Adenina/análisis , Adenina/metabolismo , Animales , Anomalías Congénitas/etiología , Citosina/análisis , Citosina/metabolismo , Aductos de ADN/análisis , Daño del ADN , Femenino , Feto/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Guanina/análisis , Guanina/metabolismo , Hidantoínas/análisis , Hidantoínas/metabolismo , Hidroxilación , Hígado/química , Embarazo , Ratas , Ratas Wistar , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Uracilo/análisis , Uracilo/metabolismo , Vitamina E/administración & dosificación
18.
Zhong Yao Cai ; 22(1): 8-10, 1999 Jan.
Artículo en Chino | MEDLINE | ID: mdl-12575054

RESUMEN

Three constituents(uracil, xanthine, hypoxanthine) were isolated from five species of leech and determined by reversed phase HPLC. The column employed was Shim-pack CLC-ODS C18(150 mm x 6 mm). The mobile phase was 0.05 mol/l ammonium phophate dibasic solution(pH = 8.4). The flow rate was 0.8 ml/min and detection was effected at 254 nm. This method is accurate, rapid and reproducible. Analytical data for five species and Whitmania pigra samples from different places were given.


Asunto(s)
Hipoxantina/análisis , Sanguijuelas/química , Materia Medica/química , Uracilo/análisis , Xantina/análisis , Animales , Cromatografía Líquida de Alta Presión/métodos , Sanguijuelas/clasificación
19.
Zhongguo Zhong Yao Za Zhi ; 24(2): 73-6, 124, 1999 Feb.
Artículo en Chino | MEDLINE | ID: mdl-12242810

RESUMEN

OBJECTIVE: To make further studies on the water-soluble components in animal drugs by determining the contents of uracil, xanthine, hypoxanthine and uridine from ten species of animal drugs. METHOD: The determination was affected by RP-HPLC, using Shim-pack CLC-ODS column(150 mm x 6 mm), 0.05 mol/L dibasic ammonium phosphate solution as mobile phase, flow rate 0.8 ml/min and detection at 254 nm. RESULTS: This method is accurate, rapid and reproducible. Analytical data for Hirudo nipponia, Eupolyphaga sinensis, Scolopendra subspinipes mutilans, Buthus martensii, Bombyx mori, Mylabris cicorri, Aspongopus chinensis, Lytta caraganae, Tabanus bivittatus and Huechys sanguinea are given. CONCLUSION: There are marked discrepancies in the contents of the four components as shown on the chromatograms, a point that may be helpful in identifying the above-cited ten species of animal drugs.


Asunto(s)
Hipoxantina/análisis , Materia Medica/química , Uracilo/análisis , Uridina/análisis , Xantina/análisis , Animales , Cromatografía Líquida de Alta Presión/métodos , Insectos/química
20.
J Pharm Biomed Anal ; 12(9): 1063-8, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7803552

RESUMEN

A capillary zone electrophoresis assay has been developed which simultaneously separates and quantifies the bacterial metabolites thymidine, uracil and p-aminobenzoic acid present at bacteriologically relevant concentrations in a supplemented minimal bacteriological medium. Sulphadiazine was used as the internal standard.


Asunto(s)
Ácido 4-Aminobenzoico/análisis , Electroforesis/métodos , Escherichia coli/química , Timidina/análisis , Uracilo/análisis , Células Cultivadas/metabolismo , Concentración de Iones de Hidrógeno
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